Grate structure



July 30, 1935.

J. W.,HULSON GRATE STRUCTURE 2 SheetsSheet 2 awveutoz 17277202120.17u2s0n Patented July 30, 1935 UNITED STATES PATENT OFFICE 10 Claims.

The invention relates to grate structures of the general type havingparallel fire-supporting ridges, grooves extending longitudinallybetween said ridges to receive and disperse the draught air, andtuyereopenings for delivering draught air to said grooves. With such grates,the ridges are prone to fuse and scale, particularly in the higher rangeof draughts and when the grate is subjected to the soaking temperature"encountered when very little draught air is being supplied, forinstance, during stand by service on stationary boilers and locomotivesheld under fire.

The principal object of the present invention is to overcome the abovedifficulty by the provision of an improved structure in which the airdischarged from the grooves flows upwardly and laterally from them incontact with the ridges, thereby so bathing said ridges with the ingoingair as to maintain them at a safe temperature.

A further object is to provide for imparting a whirling motion to theair as it leaves the grooves thereby more intimately mixing it with thecombustible gases to better support combustion.

A still further aim'is to provide, in accordance with accepted practice,for constructing the improved gate from finger bars and finger plates.

With the foregoing in view, the invention resides in the novel subjectmatter hereinafter described and claimed, description beingaccomplishedby reference to the accompanying drawings.

Fig. 1 is a partial plan view partly broken away and in horizontalsection. I

Fig. 2 is a side elevation of one of the finger plates, the finger barbeing shown in vertical section.

Fig. 3 is a vertical sectional view on line 3-3 of Fig. 1.

Fig. 4 is a similar view to Fig. 2 but showing a different form ofconstruction.

Fig. 5' is a vertical sectional view on line 55 of Fig. 4.

In the form of construction shown in Figs. 1 to 3, a portion of a grateis shown including a plurality of finger bars such as I0 and a pluralityof contacting finger plates II mounted upon each bar, the various barsand plates being preferably connected with each other 'in the mannerdisclosed in U. S. Patent No. 1,500,920, issued July 8, 1924 to myselfand William F. Bradley.

Each finger plate I I includes an elongated firesupporting ridge I2which is transversely convex as denoted at I3. Integral with theopposite sides of the ridge I2 respectively and projecting laterallyfrom the base portion of said ridge are two flanges I4 of identical sizeand shape, said flanges extending throughout the length of the ridge I2.Integral with the inner portions of 5 these flanges I4 and the baseportion of the ridge I2 is a central vertical longitudinal supportingweb I5 which is provided with a suitable hub I6 mounted upon the fingerbar I0.

The ridge I2 is of a width considerably greater than the thickness ofthe web I5 so that both said ridge and the flanges I4 project laterallyin 'opposite directions from. said web. In these projecting portions,tuyre openings I1 are formed for conducting draught air from the ash-pitinto the air-receiving grooves G which are formed between the ridges I2when the various finger plates II are positioned upon the finger barIII. The air discharged into the grooves G is discharged upwardly andlaterally from these grooves, and due to the transverse convexity of theridges I2, the air will flow laterally over and constantly bathe saidridges, keeping them at such a temperature as to prevent fusing andscaling. To facilitate this flow of air, each ridge I2 is provided witha plurality of transverse grooves I8 which preferably lead from itsopposite sides to points near the longitudinal center of the ridge.

It will be observed that the delivery ends of the tuyere openings I! arein opposed relation at opposite sides of the grooves G so that the discharging streams of draught air strike each other head-on. This causesdissipation of the streams and the discharging air flows not onlydirectly upward from the grooves G but laterally along and in contactwith the convex surfaces I3 of the ridges I2. Preferably, alternatetuyere openings at either side of each groove G are relatively large andsmall as shown, and the relatively small openings at one side of eachgroove are directly opposite the relatively large openings at theopposite side thereof. By thus admitting opposing streams of differentsizes, I have found that the air is violently whirled as it isdischarged from the grooves G, thereby facilitating intimate mixturewith the combustible gases and insuring better combustion. Thisdifference in relative sizes of opposed tuyre openings, need not becarried out entirely throughout the length of each finger plate II, inwhich connection it is to be observed that the relation of relativelylarge and small openings is not shown at the central portions of thevarious finger plates, to provide a more even distribution of metal anda stronger structure.

In Figs. 4 and 5, the finger plates l9 are very similar to those shownin my U. S. Patent No. 1,715,294 of May 28, 1929. Each plate is providedwith a relatively high step 20 and a comparatively low step 2| so thatwhen the plates are assembled, they provide the grate with longitudinalfire-supporting ridges and with draught air receiving and dispersinggrooves between said ridges. The high steps 20 have the corners thereoftoward the grooves rounded as denoted at 22 so that each ridge is givena. transversely convex form for the same purpose as above described. Theopenings 23 which admit the draught air into the grooves G arepreferably alternately large and small with the large openings at eitherside of each groove directly opposed to the small openings at theopposite side thereof, for whirling the air as above explained.

It will be seen from the foregoing that I have provided an exceptionallysimple and inexpensive construction which will not only overcome theprior difiiculty with regard to fusing and. scaling of the ridges, butwill promote more thorough combustion. As excellent results have beenobtained from the specific constructions shown, they are preferablyfollowed. However, within the scope of the invention as claimed,variations may of course be made.

I claim: I

1. A grate having parallel fire-supporting ridges, air grooves extendinglongitudinally between said ridges, and tuyre openings at opposite sidesof said grooves for conducting draf t air into said grooves and forcingsaid air upwardly and laterally from said grooves, the tuyere openingsat each side of each groove being alternately large and small with thelarge openings opposed to the small openings to whirl the air as itdischarges from the grooves, said ridges being transversely convex toallow the air to completely bathe said ridges as it discharges upwardlyand laterally from said grooves.

2. A grate having parallel fire-supporting ridges, air grooves extendinglongitudinally between said ridges, and tuyere openings at oppositesides of said grooves for conducting draft air into said grooves andforcing said air upwardly and laterally from said grooves, the tuyereopenings at each side of each groove being alternately large and small,with the large openings opposed to the'small openings to whirl the airas it discharges from the grooves, said ridges being transversely convexand having transverse air conduct 'ing grooves leading from oppositesides thereof,

allowing the air to completely bathe said ridges as it dischargesupwardly and laterally from said grooves.

3. In a grate, a finger bar, a plurality of contacting finger platesmounted thereon, said finger plates being shaped to provide parallelfire-supporting ridges and air conducting grooves extendinglongitudinally between said ridges, said finger plates having tuyre'openings at opposite sides of said grooves for conducting draft air intosaid grooves and forcing it upwardly and laterally from said grooves,the tuyere openings at each side of each groove being alternately largeand small with the large openings opposed to the small openings to whirlthe air as it discharges from the grooves, said ridges beingtransversely convex to allow the air to completely bathe said ridges asit discharges upwardly and laterally from said grooves.

4. In a grate, a finger bar, and a plurality of contacting finger platesmounted thereon, said finger plates being shaped to provide parallelfiresupporting ridges and air conducting grooves extendinglongitudinally between said ridges, said finger plates having tuyereopenings at opposite sides of said grooves for conducting draft air intosaid grooves and forcing it upwardly and laterally from said grooves,the tuyere openings at each side of each groove being alternately largeand small with the large openings opposed to the small openings to whirlthe air as it discharges from the grooves, said ridges beingtransversely convex and having transverse air-conducting grooves leadingfrom opposite sides thereof, allowing the air to completely bathe saidridges as it discharges upwardly and laterally from said grooves.

5. A finger plate comprising an elongated firesupporting ridge havingopposite substantially vertical longitudinal sides, two longitudinalflanges integral with said opposite sides of said ridge respectively andprojecting laterally-from the base portion of said ridge, and a centralvertical longitudinal supporting web integral with said base portion andsaid flanges, said ridge being of a width considerably greater than thetransverse thickness of said web, said flanges and said base portion ofsaid ridge being formed with tuyere openings leading from the lowersides of said flanges through said opposite sides of said ridge.

6. A structure as specified in claim 5; the upper side of said ridgebeing transverselyconvex.

7. A structure as specified in claim 5; the upper side of said ridgebeing transversely convex and having transverse air conducting groovesleading from said opposite sides of said ridge.

8. A structure as specified in claim 5; said tuyere openings beingalternately large and small for the purpose set forth.

9. A structure as specified in claim 5; the up-- per side of said ridgebeing transversely convex, said tuyre openings being alternately largeand small for the purpose set forth.

10. A structure as specified in claim 5; the upper side of said ridgebeing transversely convex and having transverse air conducting groovesleading from said opposite sides of said ridge, said tuyre openingsbeing alternately large and small for the purpose set forth.

JOHN W. HULSON.

